Perhaps the original app was feature complete and not a lot of work needed to be done on it? It's based on a third party password management service that open sourced its code before shuttering, so this would naturally be step one in relaunching something based on that code.

I'm one of the people running passopolis. We think that Mitro was already pretty good but we've fixed several bugs, packaged it for the Chrome store, made sure the server runs reliably etc. As the FAQ explains we changed the name to avoid confusion when Googling.

We're also not building a company around it, we've absorbed the work of keeping it running as our agency (wearewizards.io).

If we start charging it's going to be for some actually new feature, not for the current product.